Pressurized spray canisters have long been utilized as economical, convenient, and portable storage and dispensing devices, accommodating products as diverse as paint, insecticide, whipped cream, materials which are corrosive and react with metals, etc. Because of the pressurized spray canister's wide spread popularity and applicability, millions and millions of units are manufactured and sold each year throughout the world. Improvements in the design and manufacturing processes are constantly sought after by the spray canister industry, since even a very minor cost reduction per unit can quickly accumulate into large scale production savings. Moreover, depending upon the particular product to be dispensed, certain design modifications must be incorporated into the valve assembly arrangement in order to facilitate proper and consistent dispensing of the product to be dispensed.
Pressurized spray canisters typically have a cylindrical metal container or canister with an access opening which is sealed by a mounting cup and valve assembly combination. Alternatively, a metal pressure dome may seal a wider open end of the canister, with the mounting cup and valve assembly, in turn, sealingly engaging with a central opening of the pressure dome. This causes a valve stem and spray button portion of the valve assembly to be disposed a greater distance away from a top surface of the canister, which facilitates more accurate and easier product dispensing.
Two types of valve assemblies are typically provided with pressurized spray canisters. One is a vertical depression-valve assembly, where product is dispensed when the valve stem is sufficiently depressed substantially vertically along the vertical axis of the valve. The other is a tilt-valve assembly, where product is dispensed when the valve stem is sufficiently tilted relative to the vertical axis of the valve. The former is most often used in conjunction with right-angle spray buttons and actuators for spraying product radially with respect to the canister, while the later is most often used with spray-through spray buttons and actuators for providing off-axis dispensing.
In addition, it is to be appreciate that both “male” valve and “female” valves are utilized. As is well known, male valves typically include a valve stem which projects from the valve assembly out through the central aperture of the mounting cup while female valves typically do not include any valve stem which projects from the central aperture of the mounting cup. The valve stem is typically manufactured as part of the actuator and extends through the central aperture of the mounting cup to facilitate actuation of the valve assembly.
During use, once the valve stem is sufficiently depressed, e.g., either vertically or tilted (causing one side portion of the valve stem base to “bite into the gasket” while the opposite side portion of the valve stem base to be sufficiently lifted or spaced away from the gasket), the product to be dispensed from the canister is allowed to flow past this internal seal. The product to be dispensed then communicates with the one or more radial orifices, formed in the valve stem, and flows radially inwardly and vertically upward, along the passageway in the valve stem, and eventually out through a discharge outlet of a spray button or actuator, in a conventional fashion.
While the above mentioned valves have worked satisfactorily for many applications, it is noted that some of the internal components, such as springs, may react with or alter or modify one or more physical characteristics, properties and/or attributes of the product to be dispensed as such product flows through the valve assembly.